Advanced User Settings

With the Advanced User Settings the optimisation parameters can be influenced even further than the options Strut Density and Shape Quality. Furthermore, a few unsupported options are available using the Advanced User Settings like Restart, Usage of a Startspace, Symmetry and preventing an Intersection.

The Advanced User Settings can be added to a Scenario by right clicking on this and selecting the option as shown in the picture below.

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The appearing text field can be used to add Advanced User Commands to the current Generative Design Scenario.

Restart, Usage of a Startspace & Influencing the Strut Density

To influence the Strut Density even further, changes of the number of iterations, stress goal percentage and number of resolution levels can be made. These settings overwrite the selection of the Strut Density and the Shape Quality as they are only default settings for the ones described here. The table gives an overview of the default settings:

The software uses four resolution levels from coarse to fine (level 3: coarse - level 0: fine). More or less resolution levels can be added or removed. The number behind the level indicates the number of iterations calculated on this resolution level. Moreover, the stressPercentGoal for each resolution level can be changed. More information about the stresses and resolution here.

To set up these additional parameters, the Input Commands (left side of the table) need to be added to the optimisation model in the Advanced User Settings Text Field. In the picture below an example is shown. By adding these Advanced User Settings, the first (coarse) resolution level will be skipped and the optimisation starts directly at the second level. You might want to add more iterations to the remaining levels to give the optimisation the chance to reduce the material accordingly. Especially level 2 can use more iterations in this case.

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Restart (Start Space)

With the Advanced User Settings a Restart is possible. A Start Space needs to be chosen with which the optimisation will re/start.

Therefore, an already optimised STL-file is needed as Start Space. This can be exported directly from the post processing and be selected as a Start Space by clicking on the browse button. Therefore, the unit of the exported STL-file needs to be in meters (SI-Units). In most cases the Strut Density and Shape Quality settings must be changed as well using the Advanced User Settings. For a restart the same resolution level and number of to be completed iterations have to be filled in.

This way a two-stage optimisation is also possible. For a two-stage optimisation the resolution level and number of iterations must be chosen wisely and will need some fine tuning.

Symmetry

With the Advanced User Settings a symmetrical result can be realized. Therefore, the geometry and the boundary conditions have to satisfy some conditions:

• The geometry needs to be symmetrical

• The boundary conditions need to be symmetrical

  • The loads have to be applied only on a half/quarter/eighth of the part. They will be automatically mirrored and considered through the symmetry planes.

  • Attention: The loads are only allowed to be applied in the positive coordinate direction (positive coordinate half/quarter/octant)

• The displacement constraints are allowed to be applied on a volume/cell that goes beyond the symmetry plane to the other coordinate half/quarter/octant unlike loads

• The geometry needs to be located in the global coordinate origin or a local coordinate system has to be created on which the symmetry can relate to

To activate a symmetry the following commands can be typed into the Advanced User Settings Text Field:

symmetry.x (Y-Z-Plane is symmetry plane)

symmetry.y (X-Z-Plane is symmetry plane)

symmetry.z (X-Y-Plane is symmetry plane)

If the symmetry is to refer to a local coordinate system, the following command must also be entered in the Advanced User Settings

symmetry.coordinateSystemBase = CoordSystem_Coordinate_System_1

(Coordinate_system_1 is the name of the local coordinate system and can vary)

The symmetry constraint might not show exactly symmetrical designs while choosing the calculation type “Preview”. This is because of the low resolution level but will not occur once the calculation type is set to “Balanced” or “Fine Tune” and the optimisation runs through.

Tipp: Only a half, a quarter or an eighth of the model will be calculated. Thus, only a half, a quarter or an eighth of the calculating resources are needed.

Note: The symmetry option is currently an unsupported function!

Have a look at the Symmetry Tutorial here!

Preventing an Intersection

Intersections between optimisation results and the Design space are needed to create the final, manufacturable design. This ensures all functional sharp edges are available and the generative designed part is inside the boundary limits.

The intersection is done automatically for every iteration. Therefore, the defined design space is intersected with each result iteration.

If an intersection is not directly requested, the export command “noIntersection” can be added to the Advanced User Settings. In some cases the design space of the optimisation is not the one the intersection should take place with and therefore this additional command can be used. The intersection is not done for the iteration but the result is the smoothed optimisation result. For further information regarding a separate intersection with MSC Apex Generative Design have a look here.

You might also be interested in these tutorials:

• Restart Optimisation

• Symmetry Optimisation

• Intersection with Apex